1. Field of the Invention
The invention relates to a system and a method for using photoacoustic effect, and more particularly to a system and an accompanying method that apply a portion of a wave-guide probe into an organic medium so as to perform imaging according to the photoacoustic effect.
2. Description of the Prior Art
Ultrasound imaging has been widely applied to medical diagnosis. Compared to other clinical medical imaging modalities such as X-ray, CT, MRI and nuclear imaging systems, ultrasound imaging is characterized as cost effective, free of ionizing radiation, non-invasive and real-time. It can also be portable, with sub-millimeter spatial resolution, and can be used for blood flow detection. Hence, ultrasound imaging has been widely utilized to assist clinical diagnosis.
Ultrasound imaging is based on reflection and backscattering. Specifically, a probe is required for radiating a sound wave into a human body. The interaction between sound wave and the tissues inside the human body produces echoes that are detected by the probe and images are reconstructed by the system based on the received echoes.
Recently, photoacoustic imaging has also emerged as a potentially useful imaging modality utilizing light and sound to make images based on the optical absorption properties of the image object. When an object is irradiated by light, some of the optical energy is absorbed followed by thermal expansion, and thus generating detectable sound waves. Therefore, an ultrasound probe can be used to detect such sound waves and reconstruct a photoacoustic image.
Despite the widespread use and potential clinical values, in some circumstances the ultrasound probes are too big, making the transmission of sound waves difficult, if not impossible It is clear that alternative methods to transmit sound waves are highly desirable.